Of course we still have to return a `bech32` for the deprecation period. Changelog-Added: JSON-RPC: `newaddr` will now return a `p2tr` field by default. Changelog-Deprecated: JSON-RPC: `newaddr` returning a `bech32` field if `addresstype` is not specified (use `p2tr`). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>